The pair have known each other for years but Gareth insists that friendship will go out of the window for 90 minutes at the Madejski Stadium.
Full-back Chris was with us from January, 2008 until a move to Forest in July, 2009.
After three years at Forest, he's back in the Premier League following a summer switch to the Royals.
The pair were on international duty with Wales last week - Chris is pictured up against Jan Vertonghen, in action for Belgium - and will soon be re-acquainted.
"I’ve known Chris for a long time, since playing Under-17s with Wales, perhaps even younger than that," said Gareth.
"Obviously, he was at Spurs as well and we’re close mates.
"It’s like any other game. Of course, he’s my friend, but you go out there and you want to do the best for your team.
"I’m sure he will think exactly the same thing. As soon as you cross the white line you are opponents. I’ll be trying my best to beat him, he’ll try to stop me and we’ll both go for it."
Gareth expects a tough afternoon at the Madejski but, like his team-mates, is determined to secure maximum points.
"Reading have come off a good run at the end of last season, got promoted and I’m sure confidence is still high," he added. "It will be a tough game at their place but it’s a game we’re looking to win to kick-start our season."